In the detergent industry, enzymes have for many decades been implemented in washing formulations. Enzymes used in such formulations comprise proteases, lipases, amylases, cellulases, mannosidases as well as other enzymes or mixtures thereof. Commercially the most important enzymes are proteases.
A wild type subtilase that have been used in laundry is the BLAP protease disclosed in WO 91/02792.
An increasing number of commercially used proteases are protein engineered variants of naturally occurring wild type proteases Everlase®, Relase®, Ovozyme®, Polarzyme®, Liquanase®, Liquanase Ultra® and Kannase® (Novozymes a/s), Purafast®, Purafect OXP®, FN3®, FN4® and Excellase® (Genencor International, Inc.). Further, a number of variants are described in the art, such as in WO2004/041979 (NOVOZYMES A/S) which describes subtilase variants exhibiting alterations relative to the parent subtilase in e.g. wash performance, thermal stability, stability during wash or catalytic activity. The variants are suitable for use in e.g. cleaning or detergent compositions.
Variants of the BLAP protease and suitable for use in cleaning or detergent compositions have been disclosed in e.g. EP 701 605.
WO99/57155 discloses detergent enzymes such as proteases modified by attachment of a cellulose binding domain to the enzymes. It is suggested that binding the detergent enzymes such as protease to textile containing cellulose would enhance wash performance.
However, various factors make further improvement of the proteases advantageous. In particular liquid detergent compositions remain a challenge for many detergent proteases and loss of activity during storage remains a problem for many good detergent proteases. Thus despite the intensive research in protease development there remains a need for new and improved proteases that have a satisfactory wash performance and increased stability in detergent compositions.